This protocol is a phase I trial to determine the maximum tolerated dose (MTD) of CPT-11 in patients with advanced cancer. Treatment is given once every three weeks. To date, 35 patients have been enrolled, and we have determined that the MTD is 320 mg/m2 for patients with no prior abdominal/pelvic radiation therapy. For patients with prior radiation therapy, the MTD is slightly lower at 290 mg/m2. Dose limiting toxicities on this protocol have been gastrointestinal (nausea, vomiting, and diarrhea) and hematologic (primarily neutropenia). The current clinical information is being analyzed along with the pharmacokinetics. An abstract from this protocol has been published, and the manuscript is prepared. Future investigations of CPT-11 given on an every-three-week dosing schedule will be assessing patients with other advanced tumors (e.g. breast cancer, gastric cancer, and brain tumors). CPT-11 is also being combined with other agents to assess tolerability and efficacy.